From 9776c56faa47deb057b61a1796b3674553837c64 Mon Sep 17 00:00:00 2001
From: Automatic Release Builder <build@flightgear.org>
Date: Sun, 25 Oct 2020 18:26:00 +0000
Subject: [PATCH] Fix a crash (race condition) closing the launcher

When local aircraft scanning is slow, we can end up clearing
the locale while a scan is in progress, which crashes. Ensure we
abandon any in-progress scan when closing the launcher.

Sentry-Id: FLIGHTGEAR-CH
---
 src/GUI/LocalAircraftCache.cxx |  5 +++++
 src/GUI/LocalAircraftCache.hxx |  1 +
 src/GUI/QtLauncher.cxx         | 24 ++++++++++++++++--------
 3 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/src/GUI/LocalAircraftCache.cxx b/src/GUI/LocalAircraftCache.cxx
index 1918cae07..5ac8771cc 100644
--- a/src/GUI/LocalAircraftCache.cxx
+++ b/src/GUI/LocalAircraftCache.cxx
@@ -578,6 +578,11 @@ LocalAircraftCache* LocalAircraftCache::instance()
     return static_cacheInstance.get();
 }
 
+void LocalAircraftCache::reset()
+{
+    static_cacheInstance.reset();
+}
+
 LocalAircraftCache::LocalAircraftCache() :
     d(new AircraftCachePrivate)
 {
diff --git a/src/GUI/LocalAircraftCache.hxx b/src/GUI/LocalAircraftCache.hxx
index b7a73e9b8..ee63303bb 100644
--- a/src/GUI/LocalAircraftCache.hxx
+++ b/src/GUI/LocalAircraftCache.hxx
@@ -110,6 +110,7 @@ public:
     ~LocalAircraftCache();
 
     static LocalAircraftCache* instance();
+    static void reset();
 
 
     void setPaths(QStringList paths);
diff --git a/src/GUI/QtLauncher.cxx b/src/GUI/QtLauncher.cxx
index 672e94442..5c64022d8 100644
--- a/src/GUI/QtLauncher.cxx
+++ b/src/GUI/QtLauncher.cxx
@@ -53,13 +53,14 @@
 #include <simgear/package/Install.hxx>
 #include <simgear/debug/logstream.hxx>
 
-#include <Main/globals.hxx>
-#include <Main/fg_props.hxx>
-#include <Navaids/NavDataCache.hxx>
-#include <Navaids/navrecord.hxx>
-#include <Navaids/SHPParser.hxx>
-#include <Airports/airport.hxx>
 #include <Add-ons/AddonManager.hxx>
+#include <Airports/airport.hxx>
+#include <Main/fg_props.hxx>
+#include <Main/globals.hxx>
+#include <Main/sentryIntegration.hxx>
+#include <Navaids/NavDataCache.hxx>
+#include <Navaids/SHPParser.hxx>
+#include <Navaids/navrecord.hxx>
 
 
 #include <Main/fg_init.hxx>
@@ -68,10 +69,11 @@
 #include <Network/HTTPClient.hxx>
 #include <Viewer/WindowBuilder.hxx>
 
-#include "LauncherMainWindow.hxx"
 #include "LaunchConfig.hxx"
-#include "UnitsModel.hxx"
+#include "LauncherMainWindow.hxx"
+#include "LocalAircraftCache.hxx"
 #include "PathListModel.hxx"
+#include "UnitsModel.hxx"
 
 using namespace flightgear;
 using namespace simgear::pkg;
@@ -500,6 +502,10 @@ bool runLauncherDialog()
         return false; // quit
     }
 
+    // avoid a race-y crash on the locale, if a scan thread is
+    // still running: this reset will cancel any running scan
+    LocalAircraftCache::reset();
+
     // don't set scenery paths twice
     globals->clear_fg_scenery();
     globals->get_locale()->clear();
@@ -533,6 +539,8 @@ static const char* static_lockFileDialog_Info =
 
 LockFileDialogResult showLockFileDialog()
 {
+    flightgear::addSentryBreadcrumb("showing lock-file dialog", "info");
+
     QString title = qApp->translate("LockFileDialog", static_lockFileDialog_Title);
     QString text = qApp->translate("LockFileDialog", static_lockFileDialog_Text);
     QString infoText = qApp->translate("LockFileDialog", static_lockFileDialog_Info);